1. Field of the Invention
The present invention relates to the field of plastic extruded parts.
2. Discussion of the Background
Since it's introduction nearly thirty years ago, the use of polyurethane products has increased dramatically. The use of these products by builders and homeowners alike has increased because of their advantages over wood and other building materials. Their resistance to chemicals, water (including salt water exposure) and insects has made them valuable products to homes and buildings.
These products are produced using a reaction injection molding (RIM) system where two components are combined under high pressure in a mixing head and poured or shot into a mold. The mold can be made from various materials such as silicone, wood or aluminum.
Some disadvantages of this manufacturing system are they are time consuming and costly. The products are produced in a “one at a time” process. The polyurethane shot into the mold and must cure before it is removed. Once cured it is removed from the mold and the back is machined flat. The molding must also be painted or coated as part of the finishing process.
The demand by consumers for products with better performance that require less maintenance has led to new approaches in manufacturing.
The new invention accommodates these needs by a more efficient manufacturing process, which yields parts that demonstrate better characteristics.